Propeller



D. A. DICKEY. PROPELLER.

APPLICATION FILED FEB. 15, I9I9.

- mkmmsso Patented D60. 13, 1921. I

WITNESSES: INVENTOR x/J oamie/ A. D/Ckey 2 ATTORNEY srara nanrnnnnm nrcxny, or wrmznvsnune, PENNSYLVANIA, AssIGNbR T wrisrma.

arair a HOUSE ELECTRIC & WUFACTURHVGI" COMPANY, A CORPORATION OF PENNSYL-' f VANIA. I

incense.

i To all whom it'mag concern:

Be it known that I, DANIEL A'. DIGKEY, a

citizen of the United States,'anda resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Propellers, of which the following'is a specification.

My invention relates to propellers for aircraft and more particularly ,to composite propellers of hollow construction, and it has,

for its primary object, the provision of means for securing separable, hollow blades of mold-ed composite material to a metallic hub.

Heretofore, it has been customary to con struct both the hub portion and the blades of. propellers as integral parts either of wood, sheet metal or the like and, as a result, considerable difficulty has been met with in the manufacture of hollow propellers, which are desirable because of'th'ei r' lightness.

My invention comprehends a propeller structure comprising a hollow hub of metal or other suitable material towhich are secured hollow blades of suitable molded ma terial, such as'su'perimposed layers of fibrous sheet material impregnated with a hardened binder. One of the objects of my invention consists in constructing the hub and-blades in such manner that the blades may be secured to the hub at any desired pitch.

Another object which I have in view is to so construct the hub and blades that an injured blade may be readily removed from the hub and replaced by anew blade.

With these and other objects in view, my invention will be more fully described, illustrated in the drawings, in the several views of which corresponding numerals. indicate like parts, and then particularly pointed out in the claims.

Figure 1 is a central, longitudinal, sectional view of a portion of a propeller emand Fig. 4 is a transverse, sectional View taken on the line 4.& of Fig. 3, looking in the direction of the arrows.

ln practising my invention, I may form a hollow propeller blade in any suitable rnor ntrina.

Specification of Letters Patent. Patented Dec. 13., 1921 Application filed February 15, 1 919. Serial lilo. 277,243.

manner, such as by impregnating fibrous sheet material, such, for example, as paper or duck, w th a suitable binder, such as a phenolic condensation'product, superimposing the sheet material, thus treated, about a suitably-shaped core to form a propeller blade body of the desired shape, size and thickness and disposing the'body, thus assembled, in a mold. Heat and pressure may then be applied to the mold to compact and shape the material, assembled about the core,

'and .to harden its binder, after which the mold may be opened andthe finished blade may be removed. -Blades of this character inay then be secured to the ends of metallic hubs, of proper design, in a manner which will best be appreciated by reference to the threaded to receive a clamping head 18 having. an outwardly tapering frusto-conical end po'rt1on 19 of less diameter than the internal, diameter at the end of the hub. With this construction, the propeller blade 20 has. its open end proportioned to fit snugly over the frusto-conical terminal of the clamping'head 19,'and a split clamping ring 21 surrounds this end of the propeller blade, which is annular in cross section, as shown in Fig. 2. vThe ring 21 may be screwed into the end of the hub by means of a spanner wrench, openings 22 being provided in the outer edges of the ring sections to permit of such operation. The inner faces of the ring sections are beveled to contween the ring and the portion-19.

It will, of course, be appreciated that it may be desirable to form propeller blades which are solid in construction, by superimposing fibrous material and a binder and molding it in a suitably-shaped mold without the employment of any core and I have, therefore, in'Figs. 3 and 4:, disclosed means for applying my invention to blades of this character.

In these figures, a solid propeller blade 23 is formed in such manner that its innerv end portion is frusto-c0nical in shape with its largest dimension at its extremity. The

a hub 24, which may be tubular or solid, is

provided, at each end, with a cylindrical,

internally threaded recess 25, ofsomewhat.

greater diameter than the inner end of'the blade. WVith this construction, the blade 23 may be secured to the hub by the employconnecting separable blades of molded mate rial, which may be either hollow or solid in construction, to hollow hubs ofmetal or other suitable material. It should further be noted that the blades may be secured at any'desired pitch.

As various changes in details of construction are self-evident, no limitations are to be imposed upon my invention other than those indicated in the appended claims.

I claim as m invention:

1. A propel er comprising a hub having tubular internally threaded ends, clamping heads screwed into the ends of the hub and having outwardly directed tapered end portions, hollow blades of molded fibrous material and a binder'adapted, at their inner ends, to snugly engage about the terminals of the clamping heads, and-split clamping rings screwed into the ends of the hub to bind the inner ends of the blades to the 3. A propeller comprising a hub having internally threaded sockets in its ends, blades having frusto-conical shaped inner ends disposed in the sockets and split clam ing nuts engaging the inner ends of the b ades and screwed nto the sockets to bind the blades to the hub.- I 4 4. A propeller comprising a hub having internally threaded sockets in its ends, blades having their inner ends disposed in the sockets and split clamping nuts en gaging about the portions of the blades in the sockets and screwed into the sockets to bind the blades to the hub;

5. A propeller comprising a hub having internally threaded cylindrical sockets inits ends, blades having frusto-conical shaped inner ends disposed in the sockets and split clamping nuts engaging about the inner portions of the blades and screwed into the sockets to bind the blades to the hub.

In testimony whereof, I have hereunto subscribed my name this 28th day of Jan.,

I DANIEL. ADAM DICKEY. 

